a. Oil ring expander.
b. Upper oil ring side rail.
c. Lower oil ring side rail.
d. No. 2 Intermediate piston ring.
e. No. 1 Upper piston ring.
(2) Install the side rail by placing one end
between the piston ring groove and the expander.
Hold end firmly and press down the portion to be
installed until side rail is in position.Do not use a
piston ring expander(Fig. 7).
(3) Install upper side rail first and then the lower
side rail.
(4) Install No. 2 piston ring and then No. 1 piston
ring.
(5) Position piston ring end gaps as shown in (Fig.
8).
(6) Position oil ring expander gap at least 45É
from the side rail gaps butnoton the piston pin cen-
ter or on the thrust direction. Staggering ring gap is
important for oil control.FITTING CONNECTING ROD BEARINGS
Engine connecting rod bearing clearances can be
determined by use of Plastigage or equivalent. The
following is the recommended procedure for the use
of Plastigage:
(1) Rotate the crankshaft until the connecting rod
to be checked is at the bottom of its stroke.
(2) Remove oil film from surface to be checked.
Plastigage is soluble in oil.
(3) Place a piece of Plastigage across the entire
width of the bearing shell in the bearing cap approx-
imately 6.35 mm (1/4 in.) off center and away from
the oil hole (Fig. 9). In addition, suspect areas can be
checked by placing plastigage in the suspect area.
(4) Before assembling the rod cap with Plastigage
in place, the crankshaft must be rotated until the
connecting rod being checked starts moving toward
the top of the engine. Only then should the cap be
assembled and torqued to specifications.Do not
rotate the crankshaft while assembling the cap
or the Plastigage may be smeared, giving inac-
curate results.
(5) Remove the bearing cap and compare the width
of the flattened Plastigage (Fig. 9) with the metric
Fig. 6 Piston Ring Installation
Fig. 7 Installing Side Rail
Fig. 8 Piston Ring End Gap Position
Fig. 9 Measuring Plastigage Width
9 - 18 2.4L ENGINENS
SERVICE PROCEDURES (Continued)
scale provided on the package. Locate the band clos-
est to the same width. This band shows the amount
of clearance in thousandths of a millimeter. Differ-
ences in readings between the ends indicate the
amount of taper present. Record all readings taken.
Refer to Engine Specifications.Plastigage gener-
ally is accompanied by two scales. One scale is
in inches, the other is a metric scale.
(6) Plastigage is available in a variety of clearance
ranges. The 0.025-0.076 mm (.001-.003 in.) is usually
the most appropriate for checking engine bearing
proper specifications.
FITTING MAIN BEARINGS
Refer to the Engine General Information Section
for Measuring Main Bearings. For Crankshaft speci-
fications refer to Crankshaft Specification Chart.
CRANKSHAFT MAIN BEARINGS
The crankshaft is supported in five main bearings.
All upper and lower bearing shells in the crankcase
have oil grooves. The number three lower main
thrust bearing is plain. Crankshaft end play is con-
trolled by a flanged bearing on the number three
main bearing journal (Fig. 10).
Upper and lower Number 3 bearing halves are
flanged to carry the crankshaft thrust loads and are
NOT interchangeable with any other bearing halves
in the engine (Fig. 10). All bearing cap bolts removed
during service procedures are to be cleaned and oiled
before installation. Bearing shells are available in
standard and the following undersized: 0.025 mm
(0.001 in.) and 0.250 mm (0.010 in.). Never install an
undersize bearing that will reduce clearance below
specifications.
MAIN BEARING INSTALLATION
(1) Install the main bearing shells with the lubri-
cation groove in the cylinder block (Fig. 11).
(2) Make certain oil holes in block line up with oil
holes in bearings. Bearing tabs must seat in the
block tab slots.
CAUTION: Do not get oil on the bedplate mating
surface. It will may effect the sealer ability to seal
the bedplate to cylinder block.
(3) Oil the bearings and journals and install
crankshaft.
CAUTION: Use only the specified anaerobic sealer
on the bedplate or damage may occur to the
engine. Ensure that both cylinder block and bed-
plate surfaces are clean.
CRANKSHAFT SPECIFICATION CHART
Crankshaft End-Play
New Part: 0.09 - 0.24 mm (0.0035 - 0.0094 in.)
Wear Limit: 0.37 mm (0.015 in.)
Main Bearing Clearance
New Part: 0.018 - 0.058 mm (0.0007 - 0.0023 in.)
Connecting Rod Bearing Clearance
New Part: 0.025 - 0.071 mm (0.001 - 0.003 in.)
Wear Limit: 0.075 mm (0.003 in.)
Crankshaft Journal Sizes
Main Bearing Journal Diameter
Standard 60.00060.008 mm (2.362260.0003 in.)
1 st Undersize 59.97560.008 mm (2.36160.0003 in.)
Connecting Rod Journals
Standard 49.99260.008 mm (1.96860.0003 in.)
1 st Undersize 49.96760.008 mm (1.96760.0003 in.)
Fig. 10 Main Bearing Identification
Fig. 11 Installing Main Bearing Upper Shell
NS2.4L ENGINE 9 - 19
SERVICE PROCEDURES (Continued)
(4) Apply 1.5 to 2.0 mm (0.059 to 0.078 in.) bead
of anaerobic sealer MopartTorque Cure Gasket
Maker to cylinder block as shown in (Fig. 12).
(5) Install lower main bearings into main bearing
cap/bedplate. Make certain the bearing tabs are
seated into the bedplate slots. Install the main bear-
ing/bedplate into engine block.
(6) Before installing bolts, lubricate the threads
with clean engine oil, wipe off any excess oil.
(7) Install main bearing bedplate to engine block
bolts 11, 17 and 20 finger tight. Tighten these bolts
down together until the bedplate contacts the cylin-
der block.
(8) To ensure correct thrust bearing alignment,
perform the following steps:
²Step 1: Rotate crankshaft until number 4 piston
is at TDC.
²Step 2: Move crankshaft rearward to limits of
travel.²Step 3: Then, move crankshaft forward to limits
of travel.
²Step 4: Wedge an appropriate tool between the
rear of the cylinder block(NOT BED PLATE)and
the rear crankshaft counterweight. This will hold the
crankshaft in it's furthest forward position.
²Step 5: Install and tighten bolts (1 ± 10) in
sequence shown in (Fig. 13) to 41 N´m (30 ft. lbs.).
²Step 6: Remove wedge tool used to hold crank-
shaft.
(9) Tighten bolts (1 ± 10) again to 41 N´m (30 ft.
lbs.) + 1/4 turn in sequence shown in (Fig. 13).
(10) Install main bearing bedplate to engine block
bolts (11 through 20), and torque each bolt to 28 N´m
(20 ft. lbs.) in sequence shown in (Fig. 13).
(11) After the main bearing bedplate is installed,
check the crankshaft turning torque. The turning
torque should not exceed 5.6 N´m (50 in. lbs.).
CRANKSHAFT END PLAY
(1) Mount a dial indicator to front of engine, locat-
ing probe on nose of crankshaft (Fig. 14).
(2) Move crankshaft all the way to the rear of its
travel.
(3) Zero the dial indicator.
(4) Move crankshaft all the way to the front and
read the dial indicator. Refer to Crankshaft Specifi-
cation Chart for end-play specification.
Fig. 12 Main Bearing Caps/Bedplate Sealing
Fig. 13 Main Bearing Caps/Bedplate Torque
SequenceFig. 14 Checking Crankshaft End PlayÐTypical
CRANKSHAFT SPECIFICATION CHART
Crankshaft End-Play
New Part: 0.09 - 0.24mm
(0.0035 - 0.0094 in.)
Wear Limit: 0.37 mm
(0.015 in.)
9 - 20 2.4L ENGINENS
SERVICE PROCEDURES (Continued)
OPTIONAL CRANKSHAFT END PLAY CHECK
(1) Move crankshaft all the way to the rear of its
travel using a lever inserted between a main bearing
cap and a crankshaft cheek, using care not to dam-
age any bearing surface.DO NOTloosen main bear-
ing cap.
(2) Use a feeler gauge between number three
thrust bearing and machined crankshaft surface to
determine end play.
VALVE SERVICE RECONDITION
VALVE REMOVAL
(1) With cylinder head removed, compress valve
springs using Special Tool C-3422-B or equivalent.
(2) Remove valve retaining locks, valve spring
retainers, valve stem seals and valve springs.
(3) Before removing valves,remove any burrs
from valve stem lock grooves to prevent dam-
age to the valve guides.Identify valves to insure
installation in original location.
VALVE INSPECTION
(1) Clean valves thoroughly and discard burned,
warped and cracked valves.
(2) Measure valve stems for wear. Measure stem
about 60 mm beneath the valve lock grooves.
(3) If valve stems are worn more than 0.05 mm
(0.002 in.), replace valve.
VALVE GUIDES
(1) Remove carbon and varnish deposits from
inside of valve guides with a reliable guide cleaner.
(2) Using a small hole gauge and a micrometer,
measure valve guides in 3 places top, middle and bot-
tom (Fig. 15). Refer to Valve Guide Specification
Chart. Replace guides if they are not within specifi-
cation.
(3) Check valve guide height (Fig. 16).
TESTING VALVE SPRINGS
(1) Whenever valves have been removed for inspec-
tion, reconditioning or replacement, valve springs
should be tested. As an example, the compression
length of the spring to be tested is 33.34 mm (1 5/16inches). Turn tool table until surface is in line with
the 33.34 mm (1 5/16 in.) mark on the threaded stud
and the zero mark on the front. Place spring over
stud on the table and lift compressing lever to set
tone device (Fig. 17). Pull on torque wrench until
ping is heard. Take reading on torque wrench at this
instant. Multiply this reading by two. This will give
the spring load at test length. Fractional measure-
ments are indicated on the table for finer adjust-
ments. Discard the springs that do not meet
specifications. The Following specifications apply to
both intake and exhaust valve springs;
²Valve Closed Nominal TensionÐ 76 lbs. @ 38.0
mm (1.50 in.)
²Valve Open Nominal TensionÐ 136 lbs. @ 29.75
mm (1.17 in.)
(2) Inspect each valve spring for squareness with a
steel square and surface plate, test springs from both
ends. If the spring is more than 1.5 mm (1/16 inch)
out of square, install a new spring.
REFACING VALVES AND VALVE SEATS
(1) The intake and exhaust valve seats and valve
face have a 45 and a 45 1/2 degree angles.
Fig. 15 Checking Wear on Valve GuideÐTypical
VALVE GUIDE SPECIFICATION CHART
Valve Guide Diameter
Intake and
Exhaust Valve:5.975 - 6.000 mm
(0.2352 - 0.2362 in.)
Valve Guide Clearance
New Service
Limit
Intake Valve: 0.048 - 0.066 mm
(0.0018 - 0.0025 in.)
0.25 mm
(0.010 in.)
Exhaust Valve: 0.0736 - 0.094 mm
(0.0029 - 0.0037 in.)
Fig. 16 Valve Guide Height
NS2.4L ENGINE 9 - 21
SERVICE PROCEDURES (Continued)
(2) Inspect the remaining margin after the valves
are refaced (Fig. 18). Intake valves with less than 1.2
mm (3/64 inch.) margin and Exhaust valves with less
than 0.9 mm (1/32 inch.) margin should be discarded.
(3) When refacing valve seats, it is important that
the correct size valve guide pilot be used for reseat-
ing stones. A true and complete surface must be
obtained.
(4) Measure the concentricity of valve seat and
valve guide using a valve seat runout dial indicator.
Total runout should not exceed. 0.051 mm (0.002
inch.) (total indicator reading).
(5) Inspect the valve seat with Prussian blue to
determine where the valve contacts the seat. To do
this, coat valve seatLIGHTLYwith Prussian blue
then set valve in place. Rotate the valve with light
pressure. If the blue is transferred to the center of
valve face, contact is satisfactory. If the blue is trans-
ferred to top edge of the valve face, lower valve seat
with a 15 degrees stone. If the blue is transferred to
the bottom edge of valve face raise valve seat with a
65 degrees stone.²Intake valve seat diameter is 34.37 34.63 mm
(1.158 1.363 inch.)
²Exhaust valve seat diameter is 29.37 29.63 mm
(1.156 1.166 inch.)
(6) Valve seats which are worn or burned can be
reworked, provided that correct angle and seat width
are maintained. Otherwise the cylinder head must be
replaced.
(7) When seat is properly positioned the width of
intake and exhaust seats should be 0.9 to 1.3 mm
(0.35 to 0.051 inch.) (Fig. 19).
(8) Check valve tip height dimensions A after
grinding the valve seats or faces (Fig. 20). Grind
valve tip to 47.99 mm (1.889 in.) for exhaust valve
and 48.04 mm (1.891 in.) for intake valve when
installed in the head. The valve tip chamfer may
Fig. 17 Testing Valve Springs
Intake and Exhaust Valves
VALVE SPECIFICATION CHART
Face Angle
Intake and Exhaust: 44.5É-45É
Head Diameter
Intake: 34.67 - 34.93 mm
(1.364 - 1.375 in.)
Exhaust: 30.37 - 30.63 mm
(1.195 - 1.205 in.)
Length (Overall)
Intake: 112.76 - 113.32 mm
(4.439 - 4.461 in.)
Exhaust: 109.59 - 110.09 mm
(4.314 - 4.334 in.)
Stem Diameter
Intake: 5.934 - 5.952 mm
(0.2337 - 0.2344 in.)
Exhaust: 5.906 - 5.924 mm
(0.2326 - 0.2333 in.)
Valve Margin
Intake: 1.285 - 1.615 mm
(0.050 - 0.063 in.)
Exhaust: 0.985 - 1.315 mm
(0.038 - 0.051 in.)
Fig. 18 Refacing Intake and Exhaust Valves
9 - 22 2.4L ENGINENS
SERVICE PROCEDURES (Continued)
need to be reground to prevent seal damage when
the valve is installed.
VALVE INSTALLATION
(1) Coat valve stems with clean engine oil and
insert in cylinder head.
(2) Install new valve stem seals on all valves using
a valve stem seal tool (Fig. 21). The valve stem seals
should be pushed firmly and squarely over valve
guide.CAUTION: When oversize valves are used, the cor-
responding oversize valve seal must also be used.
Excessive guide wear may result if oversize seals
are not used with oversize valves.
(3) Install valve springs and retainers. Compress
valve springs only enough to install locks, taking
care not to misalign the direction of compression.
Nicked valve stems may result from misalignment of
the valve spring compressor.
CAUTION: When depressing the valve spring
retainers with valve spring compressor the locks
can become dislocated. Check to make sure both
locks are in their correct location after removing
tool.
(4) Check the valve spring installed height B after
refacing the valve and seat (Fig. 20). Make sure mea-
surements are taken from top of spring seat to the
bottom surface of spring retainer. If height is greater
than 38.75 mm (1.525 in.), install a .762 mm (0.030
inch.) spacer under the valve spring seat to bring
spring height back within specification.
(5) Install rocker arm shafts as previously
described in this section.
(6) Checking dry lash. Dry lash is the amount of
clearance that exists between the base circle of an
installed cam and the rocker arm roller when the
adjuster is drained of oil and completely collapsed.
Specified dry lash is 1.17 mm (0.046 in.) for intake
and 1.28 mm (0.050 in.) for exhaust. After performing
dry lash check, refill adjuster with oil and allow 10
minutes for adjuster/s to bleed down before rotating
cam.
REMOVAL AND INSTALLATION
ENGINE MOUNTÐFRONT
REMOVAL
(1) Support the engine and transaxle assembly
with a floor jack so it will not rotate.
(2) Remove the front engine mount through bolt
from the insulator and front crossmember mounting
bracket (Fig. 22).
(3) Remove six screws from air dam to allow
access to the front mount screws.
(4) Remove the front engine mount screws and
remove the insulator assembly.
(5) Remove the front mounting bracket, if neces-
sary (Fig. 22).
INSTALLATION
(1) Reverse removal procedure for installation and
tighten fasteners in this order. For engine mount
Fig. 19 Refacing Valve Seats
Fig. 20 Checking Spring Installed Height and Valve
Tip Height Dimensions
Fig. 21 Valve Stem Oil Seal Special Tool C4745
NS2.4L ENGINE 9 - 23
SERVICE PROCEDURES (Continued)
adjustment procedure, refer to Adjustments, Engine
Mounts in this Section.
(a) Tighten bolts 2, 3 and 4 to 108 N´m (80 ft.
lbs.)
(b) Tighten bolts 1 and 5 to 54 N´m (40 ft. lbs.).
(2) Install six screws to air dam and tighten to 12
N´m (105 in. lbs.).
ENGINE MOUNTÐLEFT
REMOVAL
(1) Raise vehicle on hoist and remove left front
wheel.
(2) Support the transaxle with a jack.
(3) Remove the insulator through bolt from the
mount.
(4) Remove the transaxle mount fasteners and
remove mount (Fig. 23).
INSTALLATION
(1) Reverse removal procedure for installation.
(2) Tighten mount to transaxle bolts to 55 N´m (40
ft. lbs.)
(3) Tighten through bolt to 75 N´m (55 ft. lbs.)
(Fig. 23).
(4) Engine mount adjustment, Refer to Engine
Mount Adjustment in this section.
ENGINE MOUNTÐRIGHT
REMOVAL
NOTE: Right mount should only be serviced as an
assembly to prevent noise, vibration and harshness
concerns.
(1) Remove the purge duty solenoid and wiring
harness from engine mount bracket.
(2) Remove the two right engine mount insulator
vertical fasteners from frame rail and loosen the one
horizontal fastener.Do not remove the large nut
located at the end of the core (Fig. 24).
(3) Remove the load on the engine mounts by
carefully supporting the engine and transaxle assem-
bly with a floor jack.
(4) Remove the vertical and horizontal fasteners
from the engine side bracket. Remove the mount
assembly.
INSTALLATION
(1) Reverse removal procedure for installation.
Tighten assembly in the following order:
a. Engine mount to rail fasteners to 68 N´m (50 ft.
lbs.).
b. The vertical engine fastener to 102 N´m (75 ft.
lbs.).
c. The horizontal fastener to 150 N´m (111 ft. lbs.).
Fig. 22 Engine Mounting-Front
Fig. 23 Typical Engine MountingÐLeft
9 - 24 2.4L ENGINENS
REMOVAL AND INSTALLATION (Continued)
ENGINE MOUNTÐREAR
REMOVAL
(1) Raise vehicle on hoist and remove the left
front wheel.
(2) Support the transaxle with a jack so it will not
rotate.
(3) Remove the insulator thru bolt from the
mount and rear suspension crossmember.
(4) Remove the four mount fasteners and remove
the mount.
INSTALLATION
(1) Reverse the removal procedure for installation.
Refer to (Fig. 25).
STRUCTURAL COLLAR
REMOVAL
(1) Raise vehicle on hoist.
(2) Remove front engine mounting bracket from
bending strut and front insulator mount.
(3) Remove bolts attaching bending strut to engine
and transaxle.
(4) Remove bolts attaching collar and strut to
engine, oil pan, and transaxle. Remove strut and col-
lar.
INSTALLATION
CAUTION: Torque procedure for the structural col-
lar and bending strut must be followed or damage
could occur to oil pan, collar, and/or bending strut.
(1) Perform the following steps for installing struc-
tural collar and bending strut. Refer to (Fig. 26):
²Step 1: Place collar into position between tran-
saxle and oil pan. Hand start only, collar to transaxle
bolt 1.
²Step 2: Install bolt 4, collar to oil pan,hand
tight only.
²Step 3: Position bending strut in place and hand
start bolt 3 into the upper transaxle hole.
²Step 4: Install bolt 2, through strut and collar.
Hand starting only.
²Step 5: Install bolt 6, strut to cylinder block,
hand tight only.
²Step 6: Install the remaining collar to oil pan
bolt 5,hand tight only.
²Step 7: Final torque collar to transaxle bolts 1 ±
3, to 101 N´m (75 ft. lbs.)
²Step 8: Install bolts 7 and 8, through strut and
into cylinder block.
²Step 9: Final torque bolts4±8to61N´m(45ft.
lbs.).
(2) Lower vehicle.
Fig. 24 Engine MountingÐRight Side
Fig. 25 Engine MountingÐRear
Fig. 26 Structural Collar and Bending StrutÐ
Removal and Installation
NS2.4L ENGINE 9 - 25
REMOVAL AND INSTALLATION (Continued)